1. Field of the Invention
The invention relates to a semiconductor device, and more particularly, to a high-voltage semiconductor device, and methods of manufacturing the same and operating the same.
2. Description of Related Art
A high-voltage element process has been widely used for Power Management IC (PMIC), switching mode power supply (SMPS) and light emitting diode (LED). In recent year, green power are emphasized, which require higher conversion efficiency and low standby power consumption, so that the LED has been widely used for lighting. Generally, LED drivers are classified into Linear LED drivers and Switch mode LED drivers.
High Voltage Linear LED circuits use High Voltage Depletion MOS or High Voltage Junction Field Effect Transistor (HV-JFET) as a current source. However, HV-JFET needs larger drift region area to form RESURF (Reduced Surface Field) and a pinch off characterization of HV-JFET is relatively less sharp. In contrast, HV-DMOS may increase drain current by utilizing voltage drop between gate and source, wherein drain current of HV-DMOS is greater than drain current of HV-JFET. Accordingly, high-voltage elements usually use HV-DMOS to accomplish less area for elements while improving performance of drain current.